APPETITE VS. HUNGER
What is Appetite?
• It is the desire to eat.
• Affected by external factors; psychological
• Often in the absence of hunger
– Example smelling/seeing fresh baked cookies
• Prompts the question: What do I want to eat?
• The appetite is concerned with the immediate
effects of eating factors including salivating,
tasting, chewing, and swallowing.
What affects appetite?
• Environment
– Temperature, humidity
• Specific appetites/cravings
– salt, “sweet tooth”
• Learned preferences
– Alcohol
– Smoking
• Pleasurable factors
– Palatability, taste, texture, odor, mouth-feel
What affects appetite?
• Social influences
– Religion, culture
• Medication influences
– Sedatives
– Prednisone
• Disease influences
– Tumor products
• Metabolic influences
– Energy requirements, insulin, various hormones,
brain signals/messengers
Ways to Combat Appetite
• Eat more fiber and less
refined carbohydrates
• Brush your teeth and
floss
• Have a glass of water
• Be consistent with eating
habits
• Eat slower
• Do something to keep
your mind off of it
What is Hunger?
• Internal drive to eat; physiological
• Controlled by internal body
• Largely affected by hormones and the Central
Nervous System
• Prompts question: When can I eat?
• Cues tell us we are hungry, such as an empty or
growling stomach, a decrease in blood glucose
levels, and alterations in circulating hormones
(e.g., increased glucagon and ghrelin and
decreased insulin).
What influences hunger?
• The Central Nervous System
– Hypothalamus
– Vagus nerve
• Peripheral Body Systems
– Hormones: insulin, growth hormone, sex
hormones, glucagon
– Stomach stretching
– Liver and adipose
What influences hunger?
• Environmental factors
– Temperature
– Humidity
– Availability
• Emotional factors
– Stress
– Mood
• Disease States
– Obesity
– Anorexia
– psychopathologies
The Hypothalamus
• Part of the brain that
controls eating
– When feeding cells are
stimulated, they signal
you to eat.
– When satiety (fullness)
cells are stimulated,
they signal you to stop
eating.
– Controls the release of
all hormones
Hormonal Control
• Endorphins
– Natural body tranquilizer that can prompt you to eat.
• Serotonin
– Neurotransmitter that is released as a result of carbohydrate intake
– High levels decrease desire toe at carbohydrate and induces calmness
• Nutrient receptors
–
–
–
–
–
In small intestine
Gives the feeling of satiety/fullness
Communicates with the brain
Informs the brain of the presence of nutrients in the small intestine
Feeling of satiety with the infusing of carbohydrates or fats in the small
intestine
Leptin and Ghrelin
• Leptin
– A hormone produced
by the adipose tissue
– Increases with larger
fat mass (and
decrease desire to
eat)
– Decreases with lower
fat mass (and enhance
desire to eat)
– Counters the actions
of ghrelin
• Ghrelin
– A hormone produced
by cells in the stomach
and pancreas
– Stimulates appetite
– Levels increase before
meals and decrease
after meals
– Stimulates the release
of growth hormone
What is Satiety
• the physiological and psychological
experience of “fullness” that comes after
eating and/or drinking.
• A number of factors influence the
experience of satiety including gastric
distention, elevations in blood glucose and
alterations in circulating hormones (e.g.,
increased insulin and cholecystokinin, and
decreased glucagon).
Making Satiety a Weapon for
Weight Management
• The concept of energy density:
– Very low. Most fruits and vegetables, skim milk, and broth-based
soups. Eat as much as you like.
– Low. Many cooked grains; cereals with low-fat milk; low-fat meats,
beans, and legumes; low-fat mixed dishes; and salads. Eat
relatively large portions.
– Medium. Includes meats; cheeses; high-fat mixed dishes; salad
dressings; some snack foods. Eat in moderation.
– High. Includes crackers; chips; chocolate candies; cookies; nuts;
butter; and full-fat condiments. Control portions carefully.
• Learn emotional and social triggers
– Ask yourself this question: "On a scale of one to 10, how hungry am I
now?"
• Fill up on fruits and vegetables, whole grains, legumes, low-fat dairy,
and foods with a high water-content.
Emotional Eating
•
•
•
Experts estimate that 75% of overeating is caused by emotions.
Many often learn food becomes comfort.
Environmental Cues to Emotional Eating:
– Social. Eating when around other people. For example, excessive eating
can result from being encouraged by others to eat; eating to fit in;
arguing; or feelings of inadequacy around other people.
– Emotional. Eating in response to boredom, stress, fatigue, tension,
depression, anger, anxiety, or loneliness as a way to "fill the void."
– Situational. Eating because the opportunity is there. For example, at a
restaurant, seeing an advertisement for a particular food, passing by a
bakery. Eating may also be associated with certain activities such as
watching TV, going to the movies or a sporting event, etc.
– Thoughts. Eating as a result of negative self-worth or making excuses
for eating. For example, scolding oneself for looks or a lack of will power.
– Physiological. Eating in response to physical cues. For example,
increased hunger due to skipping meals or eating to cure headaches or
other pain.
Rating Your Hunger
• 0: Ravenously hungry, salivating.
• 1: Hungry, belly growling.
• 2: Mildly hungry; you may need a light snack to hold you over, but
you could hold out a little longer.
• 3: Satisfied; don't need to eat any more.
• 4: More than satisfied; ate too much.
• 5: Stuffed like a Thanksgiving turkey.
• Ask yourself three questions before grabbing something to eat:
– When was the last time I ate? If it was less than 2-3 hours ago,
you're probably not feeling real hunger.
– Could a small, nutritious snack rich in fiber tide you over until the
next meal?
– Can you drink a glass of water and wait 20 minutes?
5 Tips from WebMD
•
•
•
•
•
Exercise portion control. The old expression "your eyes are bigger than
your stomach" may be sage advice. Researcher Barbara Rolls and her
colleagues at Pennsylvania State University have found that the more food
you're served, the more you're likely to eat. The theory is that the
environmental cues of portion size override the body's cues of satisfaction.
Eat foods that are bulked up with water or air, which gives them more
volume and makes them more satisfying. Increasing the bulk in your meals
helps fill your belly, signals satiety to your brain, and allows you to feel full
on fewer calories. Broth-based soups, stews, hot cereals, and cooked
grains are good examples of the foods that go the distance.
Fiber can help satisfy hunger and reduce appetite. Choose high-fiber foods
like fruits, vegetables, legumes, popcorn, and whole grains. Starting a meal
with a large salad can help you eat fewer calories during the meal because
of the fiber and water content of greens and vegetables. Also keep in mind
that fresh fruits have more fiber and water than dried ones.
Avoid the buffet line. When there are lots of choices, most people eat
more. Keep it simple, limit the number of courses, and fill up on the highfiber foods first.
Include lean protein in your meals and snacks to help them last longer in
your stomach. A handful of nuts, some low-fat dairy, soy protein, or lean
meat, fish, or chicken will tide you over for hours.